It has been a long time since I posted but I need a little help, my 4runner wont start.

What happens is that when I turn the key the motor turns over, it coughs a few times and then just keeps cranking. The motor never fires off although it tries the first time I turn the key after that the starter just turns. Where should I start trouble shooting this? ignition? fuel pump?
Any help is appreciated I am trying to avoid the cost of towing it and have some one else fix it.
-Mike